1. Field of the Invention
This invention relates to a perpendicular magnetic head, which magnetizes the magnetic layer of a magnetic recording medium moving relative to it in the direction of the thickness thereof, and a method of manufacturing the same. 2. Description of the Prior Art
The conceptional construction of the magnetic head of this kind has already been known, and it comprises a block core, a thin film core secured thereto and an exciting coil wound on both these cores. The thin film core includes a magnetic thin film of a high magnetic permeability material or a magnetic soft material such as Permalloy (Trade Name), and its tip portion extending toward the magnetic surface of the magnetic recording medium constitutes a magnetic pole section with the end thereof constituting a pole face which is in frictional contact with the afore-mentioned magnetic surface. The block core serves to support the thin film core and also has an effect of preventing the magnetic saturation of the thin film core. With this magnetic head almost all the magnetic flux produced in the block-like core or block core and thin film core is led through the afore-mentioned pole section which constitutes a magnetic path of a narrow sectional area to the magnetic surface of the medium at a high flux density. Thus, the magnetic layer of the magnetic recording medium is magnetized in the direction of its thickness over it very narrow area by the highly intense magnetic field acting in that direction. This magnetic head thus permits recording of an electric signal supplied to the exciting coil on the recording medium with high efficiency and at a high density. Although this magnetic head has various merits over the prior-art ring type magnetic head, in addition to these merits it has been desired to increase the efficiency and extend the service life of the head for practical use. These demands are particularly high in case where it is intended to employ the perpendicular magnetic head in the video tape recorder (VTR), for which rapid technical advancement is now being achieved. This is so because the VTR is required to record video signal at high sensitivity and high density as well as being small in size and having long service life.
Hitherto, however, the construction of the perpendicular magnetic head has been known only conceptionally, and no magnetic head of this type has been provided for practical use. Also, there has been known neither a concrete construction or a concrete method of manufacture for achieving improved performance and extended service life of this kind of magnetic heads.